/*
//@HEADER
// ************************************************************************
//
//                        Kokkos v. 2.0
//              Copyright (2014) Sandia Corporation
//
// Under the terms of Contract DE-AC04-94AL85000 with Sandia Corporation,
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// 1. Redistributions of source code must retain the above copyright
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// documentation and/or other materials provided with the distribution.
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// this software without specific prior written permission.
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// Questions? Contact Christian R. Trott (crtrott@sandia.gov)
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// Experimental unified task-data parallel manycore LDRD

#ifndef KOKKOS_IMPL_TASKRESULT_HPP
#define KOKKOS_IMPL_TASKRESULT_HPP

#include <Kokkos_Macros.hpp>
#if defined( KOKKOS_ENABLE_TASKDAG )

#include <Kokkos_TaskScheduler_fwd.hpp>
#include <Kokkos_Core_fwd.hpp>

#include <impl/Kokkos_TaskBase.hpp>
#include <impl/Kokkos_TaskNode.hpp>

#include <string>
#include <typeinfo>
#include <stdexcept>

//----------------------------------------------------------------------------
//----------------------------------------------------------------------------

namespace Kokkos {
namespace Impl {

template< typename ResultType >
struct TaskResult {

  enum : int32_t { size = sizeof(ResultType) };

  using reference_type = ResultType & ;

  template <class CountType>
  KOKKOS_INLINE_FUNCTION static
  ResultType * ptr( PoolAllocatedObjectBase<CountType>* task )
  {
    return reinterpret_cast< ResultType * >
    ( reinterpret_cast< char * >(task) + task->get_allocation_size() - sizeof(ResultType) );
  }

  KOKKOS_INLINE_FUNCTION static
  ResultType * ptr( TaskBase* task )
    {
      return reinterpret_cast< ResultType * >
        ( reinterpret_cast< char * >(task) + task->m_alloc_size - sizeof(ResultType) );
    }

  KOKKOS_INLINE_FUNCTION static
  reference_type get( TaskBase* task )
    { return *ptr( task ); }

  template <class TaskQueueTraits>
  KOKKOS_INLINE_FUNCTION static
  reference_type get( TaskNode<TaskQueueTraits>* task )
  { return *ptr( task ); }

  KOKKOS_INLINE_FUNCTION static
  void destroy( TaskBase* task )
    { get(task).~ResultType(); }


  //template <class TaskQueueTraits>
  //KOKKOS_INLINE_FUNCTION static
  //void destroy( TaskNode<TaskQueueTraits>* task )
  //{ get(task).~ResultType(); }
};

template<>
struct TaskResult< void > {

  enum : int32_t { size = 0 };

  using reference_type = void ;

  template <class TaskQueueTraits>
  KOKKOS_INLINE_FUNCTION static
  void* ptr( TaskNode<TaskQueueTraits>* task )
  { return nullptr; }

  KOKKOS_INLINE_FUNCTION static
  void * ptr( TaskBase* ) { return (void*) nullptr ; }

  template <class TaskQueueTraits>
  KOKKOS_INLINE_FUNCTION static
  reference_type get( TaskNode<TaskQueueTraits>* task )
  { /* Should never be called */ }

  KOKKOS_INLINE_FUNCTION static
  reference_type get( TaskBase* ) {}

  KOKKOS_INLINE_FUNCTION static
  void destroy( TaskBase* task )
    { }

  //template <class TaskQueueTraits>
  //KOKKOS_INLINE_FUNCTION static
  //void destroy( TaskNode<TaskQueueTraits>* task )
  //{ }
};

} /* namespace Impl */
} /* namespace Kokkos */

//----------------------------------------------------------------------------
//----------------------------------------------------------------------------

#endif /* #if defined( KOKKOS_ENABLE_TASKDAG ) */
#endif /* #ifndef KOKKOS_IMPL_TASKRESULT_HPP */

